An atmospheric peculiarity the Earth shares with Jupiter, Saturn, Uranus and Neptune is likely common to billions of planets, University of Washington astronomers have found, and knowing that may help in the search for potentially habitable worlds.

In a bit of cosmic irony, planets orbiting cooler stars may be more likely to remain ice-free than planets around hotter stars. This is due to the interaction of a star’s light with ice and snow on the planet’s surface.